This invention relates to improvements in log charger systems for veneer lathes. More particularly the invention relates to improvements in such charger systems having automated scanning equipment for sensing the shape of a log and positioning the log for optimum production of veneer.
In the design of veneer production equipment, the primary objectives are to maximize the yield of usable veneer from the irregularly-shaped logs from which the veneer is peeled, and to maximize the production rate of the veneer. In order to attain these objectives great effort has been expended in the development of sophisticated, automated log scanning equipment, primarily of the electro-optical type, for sensing the shape of each log and rapidly determining its longitudinal axis for optimum veneer production. Examples of such scanning systems used or usable for this purpose are contained in the following U.S. Pat. Nos. 3,736,968; 3,746,065; 3,787,700; 3,852,579; 3,890,509; 3,902,539, 3,992,615; 4,197,888; and 4,221,973. Electro-optical scanners constructed in accordance with the foregoing technology, and particularly those which rotate the log during the scanning process, are extremely accurate and have the capability of determining the location of the log axis for optimum veneer production to within a few thousandths of an inch.
The progress of log manipulating mechanisms, as opposed to scanning systems, in veneer lathe chargers is exemplified by U.S. Pat. Nos. 3,037,538, 3,664,395, 3,746,065, 3,752,201, 4,197,888 and 4,246,940. In general, all of such chargers attempt to hold the log at either a prepositioning or a scanning station to determine its optimum peeling axis, adjust the position of the log such that the optimum axis is aligned with a reference axis, and transfer the log to the veneer lathe such that the optimum axis is aligned with the rotational axis of the lathe. However the speed of log manipulation by such veneer lathe chargers has been hampered by unnecessary time lags between log manipulating steps, thereby adversely affecting production rate.